Wide variety of air purifiers on the market employ different air purification technologies, use filtration materials and components of different grade, efficiency and in different combination.
All this affects the air filtration efficiency of the air purifiers, their air purification performance, and eventually the overall air cleaning result.
Therefore, the proper selection of the air purifier is the step of greater importance, that can make all the difference in the comfort of your home or office and in the well being of you and your family.
Use the charts below to compare the air filtration efficiency of air purifiers for different types of air contaminants and select the air purifier model that best suits your specific air cleaning needs.

Air Purifiers by Air Flow Rate

Air Flow Rate (open air) represents the maximum volume of air in CFM (cubic feet per minute) the motor / fan assembly is capable to move through the unit without filters installed. It is also often referred to as "free air" or "open air".AirPura air purifiers employ one of the most Powerful, yet Energy efficient PCS electric motors rated at 560 CFM.
The one-piece integrated Motor/Fan assembly delivers the powerful air flow that is 40% higher than for most other portable air purifiers on the market.
Unobstructed air flow moves straight forward through the filters in AirPura air purifiers without changing direction and without creating any turbulence. The result is the highest air flow rate among all air purifiers in this group, matched only by AIRGLE 750 air purifiers.
On the other hand, AirFree air purifiers/sterilizers employ no motor and no fan. The purification of the air is achieved over the time through the process of a natural convectional air circulation.

Air Purifiers by Clean Air Delivery Rate

Clean Air Delivery Rate (CADR) represents the volume of pure fresh air in CFM that has to be added to the room to provide the equivalent air cleaning result provided by the air purifier. CADR of a particular air purifier depends on the Air Flow Rate, the efficiency and the amount of filter media used, and the quality of filter seal gaskets.
CADR measures the actual filtration performance of the air purifier in a real conditions with all filters installed, and therefore displays the real ability of the air purifier to clean the air from most common air contaminants such as: dust, pollen and cigarette smoke. AirPura air purifiers have the highest air flow out of the entire group of air purifiers, use high efficiency large true HEPA filter and employ high quality pressure seal top and bottom felt gaskets to eliminate polluted air by-pass. The result is the highest CADR among all air purifiers in the group. AIRGLE 750 air purifiers powered by high efficiency BLDC electric motor showed the highest Clean Air Delivery Rate (CADR) in independent laboratory tests performed by the AHAM when compared to 159 leading air purifiers. (AirPura wasn't a included in the test)

* Estimated CADR (not AHAM certified)

Air Purifiers by Room Size

It comes as no surprise, that under similar conditions, the air purifiers with higher Air Flow rating or higher CADR rate are capable to maintain the required air quality in larger room or open area. Given this fact, AirPura air purifiers and Airgle air purifiers with the highest Air FLow and CADR rating among the air purifiers we offer, and among most HEPA room air purifiers on the market, are the obvious leaders in the size of the Recommended or Maximum cleaning area.
Traditionally, the air purifier manufacturers, to make a better impression on the potential buyers about the air cleaning performance of their air purifiers, use two (2) air exchanges per hour as a default number for calculating the maximum cleaning area.
However, in most cases, this is barely enough to make the difference in the air quality noticeable.
The default number of air changes per hour used by the Association of American Home Appliance Manufacturers (AHAM) is 6 (six). This constitutes the size of the Recommended cleaning area.
According to allergists and clean air specialists, the number of air changes per hour for individuals having serious respiratory condition or a health problems should be as high as 10 or even higher.
Therefore, while selecting the right air purifier for the size of your cleaning area, always go by six (6) air changes per hour as a minimal number required to maintain the best air quality in the room.Important Facts to Remember!
1. The number of air changes per hour is calculated for the average height of the ceiling of 8 ft. The size of the cleaning area goes down proportionally as the height of the ceiling goes up.
2. The size of the maximum and/or recommended cleaning area is always provided for the air purifier operating at a highest speed setting, which is also the noisiest one(!). Therefore, if the level of noise is one of your major concerns, it is always a good idea to go with the air purifier designed for the cleaning area 30% to 40% larger than the one you intend to use the air purifier in, and operate the air purifier on a quieter Medium setting.

Air Purifiers by Energy Efficiency*

To maintain clean and healthy environment all the time, most air purifiers are designed to run 24 hours a day 7 days a week. Under those circumstances, the power consumption or the energy efficiency of the air purifier becomes the factor of major importance.
Unlike most other air purifiers on the market, Sharp air purifiers and Airgle air purifiers employ the Ultra Energy Efficient DC (direct current) electric motors. The energy consumption on Low setting for Sharp air purifiers is less than 5 Watts, and is only 13 Watts for very powerful Airgle 750 air purifiers. This is 10 to 15 times lower than for most other air purifiers on the market.
Over few year period this transforms into hundreds of dollars in savings, and makes Sharp air purifiers and Airgle air purifiers the absolute leaders in Energy Efficiency not only among the air purifiers we offer, but also among most other air purifiers on the market.

* Energy Consumption on Low Speed Setting.
** AirFree air purifier/sterilizer employs no motor/fan assembly and has only one operation mode.

Air Purifiers by Filter's Lifetime

True HEPA Filters

The lifetime of True HEPA filter (particle filter) primarily depends on the amount of filter media used, quality of the filter making process and consistency of the gap between the filter pleats.AirPura I600 air purifiers employ oversized "jumbo" HEPA filter with the largest amount of true HEPA filter media per unit in this group - 100 sq. ft. of Hospital grade true HEPA media.
The high quality (warm rolled) filter making process allows to eliminate cracking and tearing of HEPA filter media. The separators between the pleats ensure high level of consistency of the gap between the pleats and even particle distribution. All this results in the highest filtration capacity of true HEPA filter in AirPura I600 air purifiers and the longest lifetime of HEPA filter (5+ years).

*Austin Air purifiers employ true HEPA and activated carbon filters combined in one filter assembly(!). Therefore, both filters have to be replaced simultaneously. Despite, true HEPA filter can last for up to 5 years, activated carbon filter normally has to be replacement every 1 to 3 years (or even sooner). This filter's design in Austin Air purifiers shortens the lifetime of true HEPA filter. However, at the same time it gives the benefits of having a brand new fresh set of filters each time you replace the filter assembly.

** Unlike all other air purifiers in the group, AirFree air purifiers/sterilizers do not use the filters at all (filter-free operation). Therefore, this rating does not apply to AirFree air purifiers.

Activated Carbon Filter Size.

The ability of activated carbon to adsorb the chemicals is measured in percentage of its own weight or the volume. Therefore, the amount of adsorbent used in the air filtration system of the air purifier directly affects the volume of chemicals that can be trapped and held in the activated carbon and determines the filter's lifetime.AirPura air purifiers and AllerAir air purifiers employ the largest amount of adsorbent per unit - up to 26 lbs. and 35 lbs. respectively. This renders the longest lifetime of the activated carbon filters among all air purifiers in the group and most other air purifiers on the market.
*Sharp air purifiers employ washable(!) reusable(!) carbon filters. According to the manufacturer's specification if washed regularly, they can last for up to 5 years. However, to maintain the best performance of Sharp air purifiers in trapping chemicals and odors, we recommend that activated carbon filters were replaced with new ones every 1 to 2 years.
** AirFree air purifiers/sterilizers do not use the filters at all (filter-free operation). Therefore, this rating does not apply to AirFree air purifiers.

Air Purifier Off-Gassing Rate

Air Purifiers designed to clean the air from wide variety of air contaminants and air pollutants should not themselves become the source of air pollution. The possible sources of air re-contamination by air purifiers are: off-gassing from the plastic housing or plastic parts, off-gassing from hot motor windings, hot electric or electronic components, oil vapors from bearings in low quality electric motors, filter seal rubber gaskets, glues, silicon, re-introduction of chemicals and air pollutants into already filtered air by contaminated filters, etc.

AirPura air purifiers, AllerAir air purifiers, Amaircare air purifiers and Austin Air purifiers employ the all metal housing with appliance finish power coating. It helps significantly reduce the off-gassing from the above air purifiers compared to the air purifiers using the all plastic housing.
Unlike in most other air purifiers on the market, the electric motor and the electric components in AirPura air purifiers are placed in the separate chamber away from clean air flow.
This helps dramatically reduce the possibility of re-contamination of the already filtered air on its way out.
Instead of widely used rubber gaskets, to seal the filter chamber AirPura air purifiers use non off-gassing totally inert felt gaskets. Along with intermediate filters made of unbleached pesticide free cotton (available upon demand), this allows dramatically reduce the Off-gassing rate from AirPura Air Purifiers air purifiers, and makes AirPura air purifiers the cleanest air purifiers on the market.

AIRGLE 750 air purifier has the whole set of filters installed at the clean air outlet. This design of the air filtration system ensures that the filters trap all solid and gaseous air contaminants, including the possible off-gassing from the air purifier motor, before the air gets back into the room. Along with the use of the environmentally safe "green" components, this ensures one of the lowest Off-Gassing Rates from AIRGLE 750 air purifier and makes it another Best Pick in this group of air purifiers.

Air Purifier Warranty Duration

The duration of Manufacturer's limited warranty reflects the commitment of the air purifier manufacturer to the overall quality and reliability of air purifiers they offer.AirPura air purifiers come with 10-Year manufacturer's limited warranty - one of the strongest and longest warranties in the Air Purifier industry. It comprises the 5-year warranty on parts and labor. Plus an additional 5-year warranty on labor only - the most expensive part of the warranty cost.AllerAir air purifiers come with the matching 10-year limited manufacturer's warranty.Sharp air purifiers come with 1-Year Limited manufacturer's warranty. However, the high quality of DC electric motor and other air purifier electric and electronic components result in a very high level of dependability and reliability of Sharp air purifiers. In fact, it is an extremely rare even when the customers complain about Sharp air purifiers.